1. Technical Field
The present disclosure relates to an integrated circuit that is operable in a standby state.
2. Description of the Related Art
Modern highly-developed machines rely on electronic control in an ever increasing manner. Particularly, in the automotive industry, the number of integrated circuits per vehicle has increased drastically. Integrated circuits control and provide electric power to a wide variety of components, devices and applications. For example, electric motors for power window systems, in-vehicle lighting fixtures, electronic door locking means, seat heating, means for electronic rear-view mirror motion, etc. are commonly driven and controlled by integrated circuits. Communication of these integrated circuits with sensors, control units and other devices is commonly achieved over a communication bus. The integrated circuits are usually coupled to the communication bus, sometimes via an intermediate microcontroller. These integrated circuits are usually supplied with electric power from the car battery, either directly or indirectly via a voltage transformer or other power regulating device. To ensure error-free functionality of the logic circuits disposed on the integrated circuits, the voltage supplied by a power source should be above a defined threshold voltage. Many integrated circuits therefore comprise circuitry for checking the supplied voltage level.
In order to save power, many integrated circuits are operable either in a normal operation state or in a standby state. In the automotive environment, the standby state is for example entered when the vehicle is turned off, because the car battery is not being recharged. However, it is desirable to have various functions or devices working, when the vehicle is turned off. For example, the door locking mechanism, the power window systems, the in-vehicle lights, etc. are kept operable when the car is turned off. However, for the integrated circuits, which drive these devices, to correctly respond to commands from the communication bus of the vehicle, the circuitry checking the voltage level of the power source is in operation when the car is turned off. As this voltage checking circuitry draws electric power from the car battery, these integrated circuits play a substantial role in continuously discharging the car battery, which can lead to the highly undesirable case of the car battery being fully discharged and the car not being operable by a user after the car has not been used for an extended period of time.
Accordingly, it would be beneficial to provide an integrated circuit that has reduced power dissipation in a standby state.